1. Field of the Invention
The present invention relates to a method for manufacturing a liquid discharge head.
2. Description of the Related Art
A liquid discharge apparatus, such as an ink jet recording apparatus, discharges liquid from a liquid discharge head to apply the liquid onto a recording medium to thereby form an image on the recording medium. The liquid discharge head of the liquid discharge apparatus has a substrate and a discharge port formation member (nozzle layer) which is formed on the front surface side of the substrate and in which the discharge ports are formed. In general, a silicon substrate formed of silicon is used as the substrate. On the other hand, the nozzle layer is formed of resin, metal, and the like.
On the front surface side of the substrate, energy generating elements which generate energy for discharging the liquid are formed. Moreover, the substrate is provided with a liquid supply port which penetrates through the substrate and supplies the liquid to the energy generating elements. The liquid supplied from the liquid supply port passes through a flow path formed by the nozzle layer, the energy is given to the liquid by the energy generating elements, and then the liquid is discharged from the discharge ports.
The substrate is a member supporting the nozzle layer and is required to have high strength. Then, Japanese Patent Laid-Open No. 2004-148825 describes a method for forming a beam in the liquid supply port in order to increase the strength of the substrate in which the liquid supply port is formed. Specifically, the method includes first forming a mask on the back surface of the substrate, processing the substrate by a laser or dry etching, and then performing etching from both surfaces of the substrate. Since the mask is formed on the back surface side of the substrate, the silicon substrate remains on the back surface side of the substrate, and the remaining silicon substrate serves as a beam.